1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine and an image forming method.
2. Description of Prior Art
This application is based on application No. 8-343158 filed in Japan, the content of which is incorporated hereinto by reference.
When images of a plurality of documents are processed, it is known to insert a paper such as a colored paper among the documents to be processed. For example, in the apparatuses described in Japanese Patent laid open Publications 2-300855/1990 and 5-294502/1993, when images of a plurality of documents put on a document tray are processed, a special paper different from normal papers is inserted at a predetermined position among the documents. In such apparatuses, it is needed that the special paper has to be inserted by a user at a predetermined position among the documents put on a document tray. Further, it is also needed that the inserted special paper has to be removed by a user from the documents after the processing is completed. These operations are troublesome for a user. It is also proposed to start image forming after a page at which a different paper is inserted is designated beforehand with an operational panel. However, when the number of documents is large, a user has to designate the page to be inserted with much attention and this is inconvenient for a user.
An object of the present invention is to provide an image forming apparatus which designates an insertion position of paper in a simple way.
In an image forming apparatus of the invention, an image reading unit reads a plurality of documents successively to generate image data thereof, and an image forming unit forms an image on a sheet based on the image data generated by the image reading unit. On the other hand, a detecting unit detects whether a document is a specified document or not, wherein the specifying document denotes a document to be read in a state different from other documents in the plurality of documents. That is, the specifying document is designated simply by putting it in a different state. A first sheet feeding unit is provided to supply a first sheet for forming an image thereon, and a second sheet feeding unit is provided for paper insertion to supply a second sheet different from the first sheet. A controller makes the first sheet feeding unit supply the first sheet for forming an image thereon. When the document read by the image reading unit is detected to be the specifying document, the controller makes the second sheet feeding unit supply the second sheet instead of the first sheet. The image of the document specifying paper insertion may be formed on the second sheet, or no image is formed on the second sheet. In a different mode, the second sheet is inserted just before or after a normal sheet on which the image of the document specifying paper insertion is formed.
An advantage of the present invention is that a position at which paper insertion is desired can be determined easily by simply putting a document at the paper insertion position differently from other documents.